Extracting caffein from whole coffee-beans.



I H. TRILLIGH. BXTRAOTING OAFFEIN FROM WHOLEOOPFEB BEAN$..

APPLICATION IIL ED APR. 1a, 1909.

. UNITED STATES PATENT OFFICE.

nnmmcn raILLIcn, or MUNICH, GERMANY.

EXTRACTING CAFFEIN FROM WHOLE COFFEE-BEANS.

Specification of Letters Patent.

Application filed April 15, 1909. Serial No. 490,164.

Patented Mar. 29, 1910.

- specification.

My invention relates to a method of freeing coffee beans from alkaloid.

' As is wellknown, the dissolvents for extracting caifein from cofl'eebeans can with .the usual methods extract only a fraction of thecafi'ein. The reason for this resides in the fact, that the caflein ispartly present in a hardly soluble combination, and also in the fact,that the horny condition of the cell-walls of the coffee beans, moreparticularly the outer cell-layers of the same, render it difficult forthe dissolvent to penetrate mto the beans and to be removed therefrom.It is known to liberate cafi'ein by means of ammonia or other bases inorder to facilitate the extraction of the cafiein before treating thecoffee beans with dissolvents. However, in such case still considerablequantities of cafi'ein will remain in the beans, even after a longcontinued extraction.

In the method according to my invention the extraction of the cafi'em iseffected in a with a suitable volatilizable acid adapted to soften thecellulose, after which the cafl'ein 1s extracted b means of chloroformor other suitable disso vent. By the treatment of the coffee beans witha volatilizable acid, more particularly acetic acid or sulfurous acid,

not-only are the cell-walls softened, but also the hardly solublecombination containing the cafi'ein is turned into a readily solubleone. a The extraction of the cafit'ein from the treated coffee beans isthen effected in the usual manner by the known extractors. The acid, bymeans of which the cells of the coffee beans are 0' ened, can beemployed either in a watery so ution or in the condition of vapor andwhen the coffee beans are treated under pressure the action of the acidwill be increased.

When the cofl'ee beans have been treated with a dissolvent and theiralkaloid has been 7 extracted, the dissolvent and the residue of theacid, if any, are removed by evaporation.

Previous to the evaporation also a subsequent extraction of the cafi'einby means of alcohol or other suitable solvent may take place, in orderto facilitate the separation of the acid. The coffee beans after beingsubjected to a dissolvent are then completely dried and roasted in theusual manner.

As dissolvents for treating the coffee beans, chloroform, benzin,benzol, tetrachloro-carbon, as well as acetic ether can be employed.

As showing, by way of example, one form of an apparatus in which aprocess in accordance with this invention can be carried out, referenceis bad to the accompanying drawings which illustrate the apparatus invertical section.

Referring to the drawing, 1) denotes an extraction vessel surrounded byheating jacket (1. and is furthermore provided near its bottom with asieve d. The vessel b is adapted to receive the coffee beans 0.Communicating with the bottom of the vessel b is a siphonconduit p whichopens into the still e, and the latter being surrounded by the heatingjacket f. Pro ecting from the still a is a pipe 9 which opens at itsupper end in a coil 11 mounted in a cooler h. The

g. Projecting from the upper end of the vessel 1) is an outlet pipe nhaving a cut-off m and interposed between the cut-off m and the vessel 61s a pressure ga e o.

The extracting medium ows from the coil '11 into the receptacle b andonto the beans 0 and is carried over by the siphon conduit 32 into thestill 6, from which it extends up the pipe 9 and returns to the coil 2'.The conduit pipe is provided with a cut-off r. If the cut-ofi s m q, andr are closed, there can be generated in the vessel 6 by the heatingthereof throu h the medium of a heating jacket a, a su ciently h1ghnternal pressure for use in connection .wlth the method. The pressurecan be indicated by the gage 0. By openin the cut-off m the pressurewithin the vesse I claim:

A method of freeing whole coffee beans from cafi'ein which consists insoftening b can be regulated.

' ration of the caffein from the beans is fatheir cellulose and changingthe hardly solof the solvent and of the acid from the beans ublecombinations contaimng catfein into by separation. 10 readily solubleones by subjecting the Whole In testimony whereof I afiix my signature.

coflee beans to acetic acid whereby the sepa- HEINRICH TRILLIOH.

cilitated, then extracting the cafiein from In the presence ofthetreated beans by subjecting them to LoUIs MUELLER, acetic ether. andthen removing the residue MATHJIDE K. HELD.

